Process for producing alphaoxocarbonyl compound

Abstract

A process by which an α-oxocarbonyl compound useful as an intermediate for pharmaceuticals/agricultural chemicals can be industrially advantageously and efficiently produced in a high yield. The process, which is for producing an α-oxocarbonyl compound represented by the general formula (I) wherein R 1 and R 2 are as defined in the description, comprises oxidizing an α-hydroxycarbonyl compound represented by the general formula (II) with oxygen or air in the presence of a carboxylic acid and at least one vanadium compound selected from divanadium pentaoxide, divanadium trioxide, divanadium tetraoxide, ammonium metavanadate, sodium metavanadate, potassium metavanadate, triethoxyoxovanadium, tripropoxyoxovanadium, triisopropoxyoxovanadium, vanadium oxobis(acetylacetonate) and vanadium tris(acetylacetonate).

1. A process for producing an α-oxocarbonyl compound represented by the following general formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1  represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or an aralkyl group, and these groups may have substituent(s); R 2  represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an alkoxyl group, an aryloxy group, an aralkyloxy group or a group represented by the general formula —NR 3 R 4  (wherein R 3  and R 4  each independently represent hydrogen atoms or alkyl groups or are combined to form a ring), and these groups may have substituent(s), 
         which comprises oxidizing an α-hydroxycarbonyl compound represented by the following general formula (II) 
       
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are as defined above, 
         with oxygen or air in the presence of a carboxylic acid and at least one vanadium compound selected from divanadium pentaoxide, divanadium trioxide, divanadium tetraoxide, ammonium metavanadate, sodium metavanadate, potassium metavanadate, triethoxyoxovanadium, tripropoxyoxovanadium, triisopropoxyoxovanadium, vanadium oxobis(acetylacetonate) and vanadium tris(acetylacetonate). 
       
     
     
       2. The process according to  claim 1 , wherein the reaction is carried out in the presence of a carboxylic anhydride. 
     
     
       3. A process for producing an α-oxocarbonyl compound represented by the following general formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1  represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or an aralkyl group, and these groups may have substituent(s); R 2  represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an alkoxyl group, an aryloxy group, an aralkyloxy group or a group represented by the general formula —NR 3 R 4  (wherein R 3  and R 4  each independently represent hydrogen atoms or alkyl groups or are combined to form a ring), and these groups may have substituent(s), 
         which comprises a step of oxidizing an α-hydroxycarbonyl compound represented by the following general formula (II) 
       
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are as defined above, 
         with oxygen or air in the presence of a carboxylic acid and at least one vanadium compound selected from divanadium pentaoxide, divanadium trioxide, divanadium tetraoxide, ammonium metavanadate, sodium metavanadate, potassium metavanadate, triethoxyoxovanadium, tripropoxyoxovanadium, triisopropoxyoxovanadium, vanadium oxobis(acetylacetonate) and vanadium tris(acetylacetonate) to obtain a reaction mixture containing the α-oxocarbonyl compound; and a step of recovering at least part of the carboxylic acid in the reaction mixture and using it again in the reaction.